xrepomirror

A CLI tool to mirror Docker images and Helm charts from public registries to local/private repositories. Designed for air-gapped or restricted environments where workloads cannot pull directly from the internet.

Features

• Mirror Docker images via docker pull / docker tag / docker push
• Mirror Helm charts via helm pull / helm push (OCI) or Nexus 3 REST API upload
• Proxy support via configurable environment variables
• Single sources.yaml configuration file, or recursively process a directory tree of sources files
• Optional per-image destination: override to control the destination image name and tag
• Supports Python 3.6 and above

Requirements

• Python 3.6+
• docker CLI — available and authenticated to the destination registry
• helm CLI (v3) — available and authenticated to the destination registry (for Helm mirroring)

Installation

pip install xrepomirror

Or install from source:

git clone https://github.com/tkdpython/xrepomirror.git
cd xrepomirror
pip install .

Configuration

Create a sources.yaml file in your working directory. The file has two top-level keys: sources and settings.

Full example

sources:
  docker_images:
    - source: docker.io/grafana/grafana:12.3.0
    - source: ghcr.io/grafana/grafana-operator:v5.21.3
      destination: grafana-operator        # keeps source tag, renames image
    - source: quay.io/prometheus/prometheus:v3.9.1
      destination: prometheus:v3.9.1-local # explicit name and tag

  helm_charts:
    - chart: kube-prometheus-stack
      repo: https://prometheus-community.github.io/helm-charts
      version: 80.13.3
    - chart: grafana-operator
      repo: https://grafana.github.io/helm-charts
      version: 5.21.4

settings:
  destination_repositories:
    docker:
      repo: ctr.example.com
    helm:
      repo: repo.example.com/helm
      type: nexus3   # "nexus3" or "oci" (default: "oci")
  env_vars:
    HTTP_PROXY: http://proxy.local:8080
    HTTPS_PROXY: http://proxy.local:8080
    NO_PROXY: .mycompany.co.uk,.svc,.local,localhost

sources

settings

Usage

xrepomirror [--sources FILE | --sources-tree DIR] [--skip-docker] [--skip-helm]

Examples

Mirror everything using the default sources.yaml:

xrepomirror

Mirror only Helm charts:

xrepomirror --skip-docker

Mirror only Docker images using a custom config file:

xrepomirror --sources /path/to/my-sources.yaml --skip-helm

Process all sources files found under a directory tree:

xrepomirror --sources-tree ./mirror-configs

Docker image destination naming

The destination image reference is determined by an optional destination key on each docker image entry:

When no destination is given the full source reference (including the original registry) is appended to the destination repo, preserving the complete image path.

Helm destination types

OCI (default)

Charts are pushed using helm push to an OCI-compatible registry:

settings:
  destination_repositories:
    helm:
      repo: ctr.example.com/helm-charts
      type: oci

Nexus 3

Charts are uploaded via the Nexus 3 REST API (POST /service/rest/v1/components). The repo value must be in the format <host>/<repository-name>:

settings:
  destination_repositories:
    helm:
      repo: repo.example.com/helm
      type: nexus3

Proxy support

Set env_vars in sources.yaml to inject proxy settings before any network operations. Standard proxy variables are supported: HTTP_PROXY, HTTPS_PROXY, NO_PROXY (and their lowercase equivalents). Variables that are already set in the shell environment take precedence over values in sources.yaml.

Dependencies

License

MIT